Compounds In Wastewater Research Articles

Synergistic degradation of Tris (2-Chloroethyl) Phosphate (TCEP) by US/Fenton system: Experimental, DFT calculation and toxicity evaluation.

Organophosphorus esters (OPEs), exemplified by tris (2-chloroethyl) phosphate (TCEP), find extensive application in diverse industries such as construction materials, textiles, chemical manufacturing, and electronics, consequently resulting in an increased concentration of these compounds in industrial wastewater. The fundamental objective of this investigation was to examine the degradation of TCEP through the implementation of US/Fenton oxidation techniques in a solution. The findings revealed that the US/Fenton system effectively facilitated the degradation of TCEP, with the Chan kinetic model precisely elucidating the degradation process. Under optimized reaction conditions, the degradation efficiency of TCEP reached an impressive 93.18%. However, the presence of common co-existing aqueous substrates such as Cl-, HCO3-, H2PO4-, and HA hindered the degradation process. Bursting tests and electron paramagnetic resonance (EPR) studies affirmed ∙OH oxidation as the principal mechanism underlying TCEP degradation. Detailed degradation pathways for TCEP were established through the utilization of density-functional theory (DFT) calculations and GC/MS tests. Moreover, the ecotoxicological evaluation of TCEP and its intermediates was conducted using the Toxicity Estimation Software Tool (T.E.S.T.).

Water Purification Using Choline-Amino Acid Ionic Liquids: Removal of Amoxicillin.

Antibiotics are the main active pharmaceutical ingredients (APIs) for the treatment and prevention (prophylaxis) of bacterial infections, for which they are essential for health preservation. However, depending on the target bacterial strain, an efficient treatment may imply weeks of continuous intake of antibiotics, whose unmetabolized fraction ends up in the wastewater system by human and animal excreta. The presence of these chemical compounds in wastewater is known to damage aquatic ecosystems and cause antibiotic resistance of pathogenic agents, which threatens the future application of these medicines. Aqueous two-phase systems (ATPSs), an emergent extraction technology for biomolecules such as proteins and vitamins, could provide more eco-friendly and cost-effective extractive alternatives given their nontoxicity and low energetic requirements. Moreover, choline-amino acid ([Ch][AA]) ionic liquids (also known as CAAILs or ChAAILs) are considered one of the greenest classes of ionic liquids due to their favorable biocompatibility, biodegradability, and ease of chemical synthesis. In this work, partition studies of amoxicillin were performed in three ATPSs containing dipotassium hydrogen phosphate (K2HPO4) and the CAAILs (cholinium l-alaninate, [Ch][Ala]; cholinium glycinate, [Ch][Gly]; and cholinium serinate, [Ch][Ser]) at 298.15 K and 0.1 MPa. To better characterize the extract and reduce errors in quantification, the effect of pH on the intensity and stability of the UV-vis spectra of amoxicillin was studied prior to the partition studies, and computational chemistry was used to validate the molecular structure of the synthesized ionic liquids. During experimental determinations, it was observed that the extraction of amoxicillin was favored by less polar ionic liquids, achieving maximum partition coefficients (K) and extraction efficiencies (E) of K = (16 ± 6)·101 and E / % = 97 ± 2, respectively, for {[Ch][Gly] (1) + K2HPO4 (2) + Water (3)} in the longest tie-line.

Optimized preparation of Ni-Febm bimetallic particles by ball milling NiSO4 and iron powder for efficient removal of triclosan

The excessive usage and emissions of triclosan (TCS) pose a serious threat to aquatic environments. Iron-based bimetallic particles (Pd/Fe, Ni/Fe, and Cu/Fe, etc.) were widely used for the degradation of chlorophenol pollutants. This study proposed a novel synthesis method for the preparation of Ni/Fe bimetallic particles (Ni-Febm) by ball milling microscale zero valent iron ZVI (mZVI) and NiSO4. Ball-milling conditions such as ball-milling time, ball-milling speed and ball-to-powder ratio were optimized to prepare high activity Ni-Febm bimetallic particles. During the ball-milling process, Ni2+ was reduced to Ni0 and formed a coupled structure with ZVI. The amount of Ni0 on ZVI significantly affected the activity of Ni-Febm bimetallic particles. The highest activity Ni-Febm bimetallic particles with Ni/Fe ratio of 0.03 were synthesized under optimized conditions, which could remove 86.56% of TCS (10 μM) in aerobic aqueous solution within 60 min. In addition, higher particle dosage, lower pH condition and higher reaction temperature were more conducive for TCS degradation. The higher corrosion current and lower electron transfer impedance of Ni-Febm bimetallic particles were the main reasons for its high activity. The hydrogen atom (•H) on the surface of Ni-Febm bimetallic particles was mainly contributed to the removal of TCS, as reductive transformation products of TCS were detected by LC-TOF-MS. Notably, a small amount of oxidation products were discovered. The total dechlorination rate of TCS was calculated to be 39.67%. After eight reaction cycles, the residual Ni-Febm bimetallic particles could still degrade 28.34% of TCS within 6 h. Low Ni2+ leaching during reaction indicated that Ni-Febm bimetallic particles did not pose potential environmental risks. The prepared environmental-friendly Ni-Febm bimetallic particles with high activity have great potential in the degradation of other chlorinated organic compounds in wastewater.

Development of an internal two-stage upflow anaerobic reactor integrating biostimulation strategies to enhance the degradation of aromatic compounds in wastewater from purified terephthalic acid and dimethyl terephthalate manufacturing processes

In this study, we aimed to establish high-rate biological treatment of purified terephthalic acid (PTA) and dimethyl terephthalate (DMT) wastewater that minimizes the inhibitory effects of high concentration benzoate and acetate. To achieve this, we developed a novel bioreactor system and biostimulation strategy. An internal two-stage upflow anaerobic (ITUA) reactor was operated with (i) a packed bed containing green tuff medium underlying (ii) a compartment seeded with anaerobic granular sludge. Ethylene glycol was amended to stimulate syntrophic interactions. Continuous operation of the system for 1,026 days achieve an organic removal rate of 11.0 ± 0.6 kg COD/m3/d. The abundance of aromatic degraders significantly increased during operation. Thus, we successfully developed a high-rate treatment system to treat wastewater from the PTA/DMT manufacturing processes by activating syntrophs in an ITUA reactor.

The Elimination of Levofloxacin from High-Salinity Wastewater via the Electrochlorination Process

The electrochlorination (E-Cl) process has attracted much attention as it is a highly efficient method for treating organic compounds in hypersaline wastewater. In this study, the E-Cl process was utilized for the removal of antibiotics. The optimal experimental conditions were determined to be a NaCl concentration of 100 mM, a current density of 1.5 mA/cm2, a pH of 7.0, and a plate spacing of 1 cm, with a levofloxacin (LEV) degradation efficiency reaching as high as 99% using this setup. The effects of the presence of other ions and humic acid on the E-Cl process were investigated, and it was found that the degradation of LEV was not significantly affected by the presence of coexisting substances. In addition, free chlorine was identified as the primary active species for the degradation of LEV by means of a quenching experiment. It was demonstrated by 3D EEM and TOC that LEV was not completely mineralized and that intermediate products may be present. In order to reveal the degradation pathways of LEV, its degradation products were also analyzed via LC-MS, and some possible pathways of LEV degradation in this system were proposed. The successful degradation of LEV demonstrated that the E-Cl process is an efficient and promising technique for the treatment of organic pollutants in high-salinity wastewater.

A Comprehensive Approach to Azo Dichlorotriazine Dye Treatment: Assessing the Impact of Physical, Chemical, and Biological Treatment Methods through Statistical Analysis of Experimental Data

This exploration investigates integrated treatment systems combining advanced oxidation processes (Fenton and photo-Fenton) with biological methods for the effective elimination of stubborn organic compounds in simulated textile wastewater composed of azo Dichlorotriazine dye. A comprehensive optimization of key process factors including catalyst dosage, hydrogen peroxide quantity, irradiation duration, etc. was systematically conducted for both Fenton and photo-Fenton processes to realize maximum COD and color removal. Under ideal conditions (0.4 g/L photocatalyst, 1 mL/L H2O2, and 75-Watt UV intensity for 60 min), the photo-Fenton process realized 80% COD elimination and complete decolorization, meeting industrial discharge limits without needing extra biological treatment. Statistical models correlating process parameters to treatment efficiency were developed, giving important design insights. For Fenton, effluent COD exceeded discharge thresholds, so a post-biological treatment using activated sludge was essential to comply with regulations. This integrated Fenton–biological scheme utilizes synergism between chemical and biological processes for enhanced overall treatment. Notable economic benefits were achieved by photo-Fenton over conventional UV-only and UV/H2O2 methods regarding energy consumption and operating costs. Overall, this pioneering work successfully proves integrated advanced oxidation–biological systems as a superior, sustainable alternative to traditional techniques for economically removing obstinate pollutants, such as azo Dichlorotriazine dye, as it is a simulated textile wastewater treatment used to satisfy environmental standards.

A solid-state pulse power sub-nanosecond SiC DSRD-based generator with high-voltage and high repetition frequency for pulse discharge water treatment

Water treatment is one of the most important issues for all walks of life around the world. The unique advantages of the solid-state power electronic pulses in water treatment make it attractive and promising in practical applications. The output voltage, rising time, repetition rate, and peak power of output pulses have a significant impact on the effectiveness of water treatment. Especially in pulse electric field treatment and pulse discharge treatment, the pulse with fast rising time achieves the advantage of generating plasma without corona, which can avoid water heating effect and greatly improve the efficiency of the pulse generator. High repetition rate can significantly reduce the peak power requirement of the pulse in water treatment application, making the equipment smaller and improving the power density. Therefore, the study developed a high-voltage high frequency sub-nanosecond pulse power generator (PPG) system for wastewater treatment. It adopts SiC DSRD (Drift Step Recovery Diode) solid-state switches and realize modular design, which can achieve high performance and can be flexible expanded according to the requirements of water treatment capacity. Finally, an expandable high-voltage PPG for water treatment is built. The output parameters of the PPG include output pulse voltage range from 1 to 5.28 kV, rise time <600 ps (20%–90%), repetition up to 1 MHz. The experiment results of PPG application for pulse discharge water treatment is presented. The results indicate that the proposed generator achieves high-efficiency degradation of 4-Chlorophenol (4-CP), which is one of the most common chlorophenol compounds in wastewater. From experiment, the homemade system can degrade 450 mL waste water containing 500 mg/L 4-CP in 35 min, with a degradation rate of 98%. Thereby, the requirement for electric field intensity decreased. Through the further quantitative analysis, the impact of frequency, voltage, and electrode spacing on the degradation effect of 4-CP is confirmed.

A preliminary test for nitrogen recovery potential of nitrogen fixing cyanobacteria and its granules treating wastewater containing different nitrogen species

Nitrogen compounds in wastewater can be regarded as both troublesome pollutants and nutrients/resources that may be reused and recycled. Currently, nitrogen (N) removal from wastewater in most wastewater treatment plants (WWTPs) is implemented by the destructive methods like nitrification/denitrification processes, and little attention has been paid to recovery and recycle of N resource in WWTPs. In this preliminary study, the granulation of cyanobacteria (i.e., Aphanizomenon flos-aquae Ralfs ex Bornet &Flahault) was achieved, and comparison was made in terms of N recovery/fixation potential when treating wastewater containing different N species. During the granulation process, the settleability indicated by sludge volume index at 5 min (SVI5) and biomass concentration varied from initially > 3000 mL/g and 0.2 g/L to 59 mL/g and 1.2 g/L, respectively. This observation suggests biogranulation may be utilized to effectively and simultaneously cultivate and harvest cyanobacteria, greatly reducing energy consumption and operation costs. Both cyanobacteria and its granules were found to remove 57–100 % of NO3–-N in 5 days under N2 recirculation at an initial NO3–-N of 15.0 mg/L. Compared to the seed cyanobacterial cells, after 3-day batch test the granular biomass contained 83 % higher total N content, about 73.3 mg N in comparison to 40.0 mg N for per gram of biomass under the same N2 recirculation condition, 236 % more proteins, and 115 % times higher N fixation capability. Results from this work can provide a promising solution for N recovery/fixation with reduced N loss/emission from WWTPs and then create nitrogen bioeconomy in wastewater industry.

Degradation of pharmaceutical pollutants in different soils by photocatalytic treatment under solar irradiation

Pharmaceutical compounds are chemicals widely applied for the treatment and prevention of human/animal diseases. Wastewater treatment plants (WWTP) are identified as one of their main transfer pathways to aquatic environment since traditional wastewater treatments do not completely remove them. Agricultural irrigation with reclaimed water from WWTP effluents is a growing strategy in areas where water scarcity is a limiting issue. However, the residual presence of these compounds in wastewaters facilitates a new terrestrial route of environmental exposure, increasing the risks of soil pollution and giving rise to dangerous situations for human health and the environment. In this study we have evaluated the effectivity of TiO2 photocatalysis using solar irradiation for the degradation of four contaminants (diclofenac, ibuprofen, ketoprofen and sulfadiazine) in different soil matrices. Influential parameters of photocatalytic process (TiO2 dosage and soil moisture content) were optimized at laboratory scale using UV-LED lamps as light source. Solar remediation trial was performed exposing polluted soils to different treatments (in presence and absence of photocatalyst) during August 2023. After 50 h of solar exposure degradations of these pharmaceuticals reached 97.8–99.5 %, 99.7–100 % and 83.2–97.5 % for soils S1, S2 and S3 respectively. For all compounds, removal followed the order S2 > S1 > S3, in coincidence with the lesser organic matter content of soils. Results suggest that TiO2 photocatalysis under sunlight irradiation could be a useful tool for remediating soils polluted with pharmaceutical residues.

Ordered mesoporous hairbrush-like nanocarbon assembled microfibers for solid-phase microextraction of benzene series in oilfield sewage.

The development of advanced functional nanomaterials for solid-phase microextraction (SPME) remains an imperative aspect of sample pretreatment. Herein, we introduce a novel SPME fiber consisting of graphene fibers modified with ordered mesoporous carbon nanotubes arrays (CNTAs) tailored for the determination of benzene series in oilfield wastewater, which is synthesized by an ionic liquid-assisted wet spinning process of graphene nanosheets, followed by a precisely controlled growth of metal-organic framework and subsequent pyrolysis treatment. The resulting robust microfiber structure resembles a "hairbrush" configuration, with a crumpled graphene fiber "stem" and high-order mesoporous CNTAs "hairs". This unique architecture significantly enhances the SPME capacity, as validated by gas chromatography-mass spectrometry. The hairbrush-like nanocarbon assembled microfibers possess structural characteristics, a high specific surface area, and numerous binding sites, offering efficient enrichment of benzene series compounds in oilfield wastewater, including benzene, ethylbenzene, m-xylene, p-xylene, and toluene. Our analysis demonstrates that these microfibers exhibit broad linear ranges (0.2-600μg L-1), low detection limits (0.005-0.03mg L-1), and excellent repeatability (3.2-5.5% for one fiber, 2.1-6.7% for fiber-to-fiber)for detection. When compared to commercial alternatives, these hairbrush-like nanocarbon-assembled microfibers exhibit significantly enhanced extraction efficiency for benzene series compounds.

The Aerobic Granules Process for Wastewater Treatment: From Theory to Engineering

Aerobic granules are small, dense aggregates of microbial cells that form naturally in aerobic wastewater treatment systems. They are characterized by their spherical shape, strong structural integrity, and ability to rapidly settle. These granules are formed through a self-immobilization process where different microbial species coalesce to degrade organic and inorganic compounds in wastewater. This study summarizes the development of aerobic granulation technology in wastewater treatment and the mechanism of aerobic granules’ formation, analyzes the characteristics and the factors affecting the aerobic granules’ formation, and presents practical engineering examples of its application from pilot-scale to full-scale operation.

Investigation on pulsed-electrocoagulation process for the treatment of wet coffee processing wastewater using an aluminum electrode

The use of conventional direct current-electrocoagulation in wastewater treatment is limited by its drawbacks, which include electrode passivation, high energy consumption, and significant sludge generation. Therefore, to address these issues, pulsed-electrocoagulation (PECP) has been developed. The PECP is an advanced wastewater treatment technique that uses intermittent electrical pulses to target and break down organic compounds in wastewater. It offers several benefits, including enhanced removal of organic compounds, reduced chemical consumption, energy efficiency, treatment of complex wastewater composition, pathogen inactivation, environmental compliance, and potential for water reuse. In this research, removal efficiency of % Chemical Oxygen Demand (COD), % Color, % Turbidity, % phosphate, and %nitrate was investigated for the wet coffee processing wastewater by using PECP and the obtained results as the COD-98.75%, color-99.92%, turbidity-99.00%, phosphate-99.02%, and nitrate-98.83%, respectively. Independent variables were the major significant factors and the optimum value was investigated and obtained at pH of 7, electrolyte dosage of 0.75 g L−1, electrolysis time of 45 min, and current of 0.45 Amp. As a result, PECP with NaCl and CaCl2 as an electrolyte is an effective treatment technique for pollutant removal from wastewater. As a consequence, the specific benefits may vary depending on the system design, operational parameters, and wastewater characteristics. The pilot-scale studies and optimization are essential for assessing PECP feasibility and performance.

The impact of ozone treatment on the removal effectiveness of various refractory compounds in wastewater from petroleum refineries

Large volumes of wastewater are generated during petroleum refining processes. Petroleum refinery wastewater (PRW) can contain highly toxic compounds that can harm the environment. These toxic compounds can be a challenge in biological treatment technologies due to the effects of these compounds on microorganisms. These challenges can be overcome by using ozone (O3) as a standalone or as a pretreatment to the biological treatment. Ozone was used in this study to degrade the organic pollutants in the heavily contaminated PRW from a refinery in Mpumalanga province of South Africa. The objective was achieved by treating the raw PRW using ozone at different ozone treatment times (15, 30, 45, and 60 min) at a fixed ozone concentration of 3.53 mg/dm3. The ozone treatment was carried out in a 2-liter custom-designed plexiglass cylindrical reactor. Ozone was generated from an Eco-Lab-24 corona discharge ozone generator using clean, dry air from the Afrox air cylinder as feed. The chemical oxygen demand, gas chromatograph characterization, and pH analysis were performed on the pretreated and post-treated PRW samples to ascertain the impact of the ozone treatment. The ozone treatment was effective in reducing the benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds in the PRW. The 60-min ozone treatment of different BTEX pollutants in the PRW resulted in the following percentage reduction: benzene 95%, toluene 77%, m + p-xylene 70%, ethylbenzene 69%, and o-xylene 65%. This study has shown the success of using ozone in reducing the toxic BTEX compounds in a heavily contaminated PRW.

Mono and polycyclic aromatic hydrocarbons in waterpipe wastewater: Level and ecotoxicological risk assessment

Increasing of tobacco consumption around the world has led to the production of a large volume of waterpipe wastewater that enter the environment (e.g., coastal areas)and threaten aquatic creatures. However, until now, no research has been carried out on the amounts of monocyclic and polycyclic aromatic hydrocarbons (PAHs) in hookah wastewater. In the current study, the levels of PAHs and BTEX compounds in waterpipe wastewater resulting from the use of different tobacco brands were determined and their eco-toxicological effects were also evaluated. The mean levels of ƩPAHs in waterpipe wastewater of Al Tawareg, Al-Fakher, Nakhla, Tangiers and traditional tobacco brands samples were 3.48 ± 1.65, 3.33 ± 1.52, 3.08 ± 1.25, 2.41 ± 0.87 and 0.70 ± 0.13 μg/L, respectively. The mean levels of ƩBTEX in waterpipe wastewater of Al Tawareg, Al-Fakher, Nakhla, Tangiers and traditional tobacco brands samples were also 2.53 ± 0.61, 2.65 ± 0.78, 2.51 ± 0.72, 2.35 ± 0.56, and 0.78 ± 0.12 μg/L, respectively. The maximum level of PAHs and BTEX compounds in all brands/flavors samples were for naphthalene (Naph) and toluene, respectively. The concentrations of some PAHs (fluoranthene (Flrt), anthracene (Ant), benzo(b)fluoranthene (BbF), benzo(b)fluoranthene (BkF), benzo (g,h,i)perylene (BghiP) and dibenzo (a, h) anthracene (DahA)) and BTEX compounds (benzene) in the waterpipe wastewater samples were more than recommended guidelines and standards by the international reputable organizations such as World Health Organization (WHO) for water quality. Waterpipe wastewater can be introduced as an important origin for the release of these dangerous contaminants into the environmental matrixes. Therefore, more stringent regulations should be considered for the safe disposal of such hazardous wastes including waterpipe wastewater.

Nitrogen-doped carbon quantum dots based on deep eutectic solvents precursors to detect Cr6+ in environmental water

Hexavalent chromium is the main compound in industrial wastewater, which is highly toxic and seriously pollutes the environment and endangers human health. The excellent fluorescence performance of carbon quantum dots (CQDs) is widely used to detect heavy metal ions. Carbon quantum dots (CQDs) with excellent fluorescence performance is widely used to detect heavy metal ions. However, the quantitatively structure of CQDs is different to control in the formation due to the uncertain-complex of biomass-based materials. In this work, nitrogen-rich CQDs (N-CQDs) based on 4-A-1,2,4-TZ and glycerol deep eutectic solvents (DESs) was prepared by one-step hydrothermal method. The prepared N-CQDs exhibited excellent fluorescence stability. The response of the N-CQDs to Cr6+ was linear in the range of 5–100 μM and a detection limit of 0.7043 μM. The results show that N-CQDs can achieve the detection of Cr6+ well. Satisfactory recovery of Cr6+ was also obtained by measuring in the wastewater.

Electric field coupled with Fe3O4 modified biochar to enhance anaerobic degradation of phenolic compounds in coal gasification wastewater (CGW)

Anaerobic treatment of coal gasification wastewater is usually limited by the inhibition of high concentration of phenolics. In this study, the Fe3O4 loaded biochar (FeBC) coupled with electric field (E-FB) was used to enhance anaerobic phenolics degradation. E-FB significantly accelerated anaerobic removal of phenol, p-cresol and 3,5-xylenol with methane production improved by 84.2 % compared to the control, where FeBC contributed most. E-FB improved anodic oxidation capacity, adsorption-biodegradation and Fe (III) reduction process, which resulted from the synergistic effects between electric field and FeBC. E-FB significantly enhanced the microbial activity and extracellular electron transfer (EET) in the suspended sludge with the maximum electron transfer system activity (132.9 %), cytochrome C (7.2 nmol/g MLSS) and adenosine triphosphate contents (87.8 nmol/ g MLSS) obtained. Compared with FB, E-FB stimulated the secretion of proteins and humic acid-like substances in extracellular polymeric substance, which could contribute to higher EET efficiency. More abundant phenol degrading bacteria, dissimilatory iron reducing bacteria, electroactive bacteria and potential direct interspecies electron transfer (DIET) partners (e.g., Geobacter and Methanobacterium) were enriched in E-FB especially on the anode. The benzoyl-CoA pathway on the anode and CO2-reduction methanogenesis (possibly via DIET) in the suspended sludge and anode were improved in E-FB.

Solid dicarboxylic acid assisted deliming in beamhouse to reduce nitrogen compounds in tannery wastewater

In leather manufacturing, ammonia salts in deliming operations contribute to the significant addition of ammonia-nitrogen (NH3–N) into wastewater. Wastewater containing NH3–N serious affects aquatic life and the operations of effluent treatment plants. In this study, the strategy of reducing NH3–N released into tannery wastewater, uses non-ammonia deliming agent-solid dicarboxylic acid (malonic acid) to replace the conventional deliming agent (ammonium sulfate). Utilizing a laboratory experiment, a pilot scale test was carried out and found to be almost comparable with the former experimental work. The generated delimed wastewater, delimed pelts, and manufactured crust leathers were subjected to various physicomechanical analyses. Results revealed that the reductions of NH3–N, TKN, and hydroxyproline amounted, respectively, to 98.78%, 88.69%, and 26.9%, compared to conventional deliming agents. The other pollutants, namely TDS, BOD, COD, and EC were significantly reduced. The physicomechanical properties of the crust leathers met the standard requirements. SEM images of delimed pelt and crust leathers revealed a similar fiber structure. The wastewater emitted during deliming with malonic acid is probably an easier way to conduct effluent treatment by reducing nitrogen pollution. This investigation is a novel approach to finding a viable technology that can satisfy the need for modern leather manufacturing being done in environmentally friendly ways.

How the chitosan structure can affect the adsorption of pharmaceuticals from wastewaters: An overview

The disposal of pharmaceutical compounds in wastewater is a significant environmental and health challenge. These drug residues can have adverse effects on aquatic ecosystems and human health. Chitosan, a natural polysaccharide derived from chitin, is promising as an effective material for adsorbing pharmaceutical waste due to its unique chemical structure containing amino and hydroxy functional groups that facilitate interactions with organic molecules in wastewater. Chitosan can adopt various structural forms, such as hydrogels, nanoparticles, beads, membranes, fibers, and aerogels, which offer opportunities to optimize its performance in adsorbing drug waste. In this review, which includes articles published in the last 5 years, the influence of chitosan's structural forms, particularly on the adsorption of pharmaceutical compounds in wastewater is explored. Furthermore, the different synthesis and fabrication methods for each chitosan form and highlight their characteristics, advantages, and specific applications, are discussed. Additionally, this review delves into the adsorption mechanisms involved in each form.

Compound Similarity Network as a Novel Data Mining Strategy for High-Throughput Investigation of Degradation Pathways of Organic Pollutants in Industrial Wastewater Treatment.

Identification of degradation products and pathways is crucial for investigating emerging pollutants and evaluation of wastewater treatment methods. Nontargeted analysis is a powerful tool to comprehensively investigate the degradation pathways of organic pollutants in real-world wastewater samples but often generates large data sets, making it difficult to effectively locate the exact information on interests. Herein, to efficiently establish the linkages among compounds in the same degradation pathways, we introduce a compound similarity network (CSN) as a novel data mining strategy for LC-MS-based nontargeted analysis of complex wastewater samples. Different from molecular networks that cluster compounds based on MS/MS spectra similarity, our CSN strategy harnesses molecular fingerprints to establish linkages among compounds and thus is spectra-independent. The effectiveness of CSN was demonstrated by nontargeted identification of degradation pathways and products of organic pollutants in leather industrial wastewater that underwent laboratory-scale activated carbon adsorption (ACD) and ozonation treatments. Utilizing CSN in interpreting nontargeted data, we tentatively annotated 4324 compounds in the untreated leather industrial wastewater, 3246 after ACD, and 3777 after ACD/ozonation. We located 145 potential degradation pathways of organic pollutants in the ACD/ozonation process using CSN and validated 7 pathways with 15 chemical standards. CSN also revealed 5 clusters of emerging pollutants, from which 3 compounds were selected for in vitro cytotoxicity study to evaluate their potential biohazards as new pollutants. As CSN offers an efficient way to connect massive compounds and to find multiple degradation pathways in a high-throughput manner, we anticipate that it will find wide applications in nontargeted analysis of diverse environmental samples.

Role of carbon nanotubes in remediation of pharmaceutical wastewater

AbstractThe discharge of wastewater from the pharmaceutical industry poses risks of detrimental effects on various ecosystems. The presence of hazardous substances in pharmaceutical wastewater is a matter of global concern due to its association with multiple disorders, including disruptions in endocrine hormones and significant chronic toxicity. As research in this field continues to grow, the valorization to nanotechnology‐based treatment of industrial wastewater approaches. One prominent focus of recent research is the utilization of nanomaterials, particularly carbon nanotubes (CNTs), in treating pharmaceutical wastewater, aligns with the goals of sustainable development. CNTs demonstrate potential in efficiently mineralizing pharmaceutical compounds in wastewater, offering cost‐effectiveness, ease of handling, and efficacy. Additionally, CNTs possess the capability to remediate pharmaceutical wastewater at a relatively low cost, with the advantage of being recyclable. This review provides an overview of the diverse applications of various CNTs for the removal of pharmaceutical compounds from wastewater, emphasizing the mechanisms of adsorption and degradation of these compounds using CNTs. Furthermore, it sheds light on the application of CNTs in photocatalysis as an economically viable and efficient solution.